Conversion functions are used to convert between database representations
of types and scheme representations of types. They are all straightforward.

SQLite is SQL92 compliant, so for all strings, the single quote must be
escaped. A simple pregexp-replace* call is used to escape the single
quotes. This function could be made more efficient, using a loop, or
even a C function to do the same.

The date types aren't known in SQLite, so a date type is constructed
from the bigloo date type, using a broken ISO8601 encoding (the zone
info part is not there).

The interpretation back from the database is done by expecting the
same broken ISO8601 encoding. No checking is done for the parts of the
strings; so, the
precondition for the use of this function is, that the given string
conforms to the previous definition.

The connection function is called from the closure provided
by sqld-sqlite-new, when it is called with the 'connect
argument. It returns a closure that is used for further
command processing and that has a connection to the SQLite
database.

The commands to be processed are placed in a cond structure,
with the probably most commonly used commands at front.

Supportive functions are defined within the closure, to handle
the interfacing for queries to the C part and fetches.

Now for the main function that this driver provides: sqld-sqlite-new.
This function takes connection-info as an argument, which must be
an SQLite database. It returns a closure that handles the 'connect,
'clean, 'name and 'version calls. It is a very simple function.

The 'version call returns the major version number of SQLite * 100 +
the minor version number.